Telegraph keyboard transmitter



May 26, 1942.

v. R. KIMBALL ETAL ,TELEGRAPH KEYBOARD TRANSMITTER- FI G. f5"

lNvEnrons ATTORNEY Patented May 26, 1942 TELEGRAPH KEYBOARD TRANSMITTER Vernon R. Kimball, Union City, N.J., and'Robert F. Dirkes, Jamaica, N. Y., assignors toV VThe Western Union Telegraph Company, New York,

.N. Y., a corporation of New York Application January 17, 1941, Serial No. 374,824

11 claims.- (ci. irs-753.1)

This invention relates primarily to telegraph transmitters and more particularly to that type of telegraph transmitters known as keyboard transmitters wherein a plurality of key levers are employed, the actuation of which one at a time causes the transmission of representative signal code groups to a sending circuit.

It is oneof the objects of the present invention to provideV a keyboardtransmitter that is positive in operation, capable ofY operating at a high rate of speed, and comprises a minimumy number of Velements of simplified design and arrangement.

Another object of the invention is to provide a keyboard transmitter which, because of its simplified design and minimum number of parts employed, is easy to adjust and *maintainV and relatively cheap to manufacture.

Still another object of the invention is to provide a keyboard transmitter wherein the releasev of the rotatable distributor member is effected by a light and substantially uniformtouch on the keys.

A more specic object of the invention resides in the releasing and stopping arrangement for the rotatable distributor member employed in such keyboards.

These and other objects of the invention will be more apparent whentaken in conjunction with the following detailed description and the accompanying drawing, in the latter of which:

Fig. 1 is a perspective view showingV the prin- 4 cipal elements of the keyboard'and the manner in which they cooperate with one another;

Fig. 2 is an enlarged vertical sectional View of the stop arms and stop gates for controlling the rotation of the rotatable distributor member;

Figure 3 shows the relative positions of the stop gates employed in conjunction with the rotatable Adistributor and the manner in which they cooperate'with associated blocking members;

Fig. 4 is a view showing some'of the key levers in section, together with a permutation bar and a cooperating contact controlling member; and

Fig. 5 is a developed view of the distributor, together with the transmitting contacts for controlling the signalcode groups that are transmitted by the distributor.

Referring rst to Fig. 1, a shaft II which is suitably journaled in journals (not shown) has xed thereto for rotation therewith a gear I2.

of the'Well-known types, such as a synchronous motor or-a suitably governed direct current motor. In alignment with the shaft II is a transmitting or' distributor shaft I,3 and through a friction clutch, indicated in general by reference numeral I4, the shaft I3 tends to rotate with the constantly rotating shaft II but is normally prevented from doing so by means hereinafter described., l

Insulatively supported on the right hand end of the transmitting shaft I3 and adapted to rotate therewith is a brush I4 whichV cooperates with a solid ring I6 anda segmented ring II. A

The rings I6 and' I 'I are stationary relative to the shaft I3, and as the latter rotates, it' being released for rotation as hereinafter described, the brush I4 successively bridges'the segments of the segmented ring I'I with the solid ring I6. The solid ring I6 is connected to the line or outgoingr circuit L while the segments of the segmented ring I1 are connected to circuit controlling means whereby signal codes are-:set up thereon. Therefore, asl the brush I4 successively bridges the segments of the ring I1 `with the solid ring I6, signal codes areV transmitted to the line L. As shown in Figs.`1 and 5, the normal stop position of the shaft I3 is such that the brush 'I4 bridges the segment R or rest segment of the ring I1 with the solid ring I6. `The rest segment R of the segmented ring Il has potential applied thereto'and hence with the brush in'its vnormal stop position a closed line condition prevails on the line L, it being assumedthat the opposite end of the line L is grounded through an appropriate receiving instrument. i

Although, as will be pointed out in detail hereinafter, the keyboard in 'its preferred embodiment is arranged to transmit so-called startstop code groups representing the actuated key levers wherein open and closed'line conditions arey established on the line L, with each code group being preceded by a start impulse of open line'condition and followed by a rest impulse of closed line condition, the keyboard could be adapted by obvious arrangements t0 transmit code groups composed of opposite polarities.

The transmitting vshaft I3 has Xed thereto for rotation therewith by means such as 'a key I8 two stop arms, a normal stop arm I9 and an auxiliary stop arm 2|.v :The stop arms I9 and 2| have at the free ends thereof axially extending projections which cooperate with associated stopfgates 22 and 23,'res'pectively. The stop gates 22 and 23, hereinafter referred to as the normal stop gate andthe auxiuary stop sate, respectively, are

tend to pivot the same in a clockwise direction n about the stud 24, as shown in Figs'. l and 2, and as limited by a stationary stop 28.

The stop gates 22 and 23 have projections 29 extending from the upper sides thereof and each stop gate is sopositioned on the stud 24 that itY is in alignment with an associatednejof the stop arms on the shaft I3. The stop gates 22 Aand 23 also have leftwardly extending arms 3l, which as shown in Figs. 1 and 2, have associated therethe actuation or depression of a key lever 46, the underside thereof cooperates with the sloping surfaces such as 50 of the permutation bars 5I to move the latter longitudinally to the left and right in Various combinations to represent the actuated key lever. Depending upon the positions of the permutation bars as moved by the kkey levers, either oneorthe other of two line conditions are transmitted in a' manner pointed out' in following paragraphs. Also extending beneath the key levers 46 is a so-called release f bar 52' wl'1ich hasarranged on the upper side with the upper ends of individual blocking members or interponents 32. Fingers 30 en the upthereof and has extending horizontally from .the l upper right hand corner anarm 36. A spring 31 attached 'to the arm 36 Vnormally tends to pivot the pivot'plate 34.inv`a clockwise direction to hold thezarmV 36 against the; up'per end 'of an adjustablestop 38. .i Thegadjustable stopi38'isic1amped in position .by a screw 39. and has the lower end ofthe spring 31 anchored thereto.` A spring 4|. is v attached to the blocking'members 32 and tends to` pivot the sameoppositefdirections `to.-bring Y thengers `3i1' at the upper endsthereof together. Howevenzadjustable arms 43 clamped tothe pivot plate `34`by a stud 44 keep the ends of the ngers Saat the upper endsjof the blocking members 32 spacedapart.. :The left` hand arm 43 on the -pivot plate34yis adjusted so that when the .arm 36V of thetpiv'ot plate engages the stop: 38, the inner end 'o'f the nger 30 on the left hand blocking member 32is beneath .the left' hand stop gate 22. kWith thepivct,v plate 34 its jnormal positionas5shown in Fig. Y1, the normal stop arm I9 engages theileftv handfstopjgateV 22 topivot the same ina counter-clockwise direction and bring the underside of the leftwardly extending arm 3I thereof into engagement with the top of the iinger 3U on the leftl hand blocking member 32. Thsthe transmitting shaft I3 is stopped in its normal stop position and the manner' in which it is released to normally make one `revolution in response to the 'actuation of a key lever will now bedscribed.J-"' J I i 'Only one of the key levers 46 is shown in Fig. l, there being the usual number thereof, which are :pivotedattheir .rear 'ends on`a pivot rod 41 andihave key designating caps such as 48 on the frontfree' ends.` lIndividual.springs such as 49 hold the k'ey levers 46 'elevated in their normal position'and return the same to their normal p'osition following theoperation thereof.' As in the usual arrangement in .telegraphkeyboarda a set of permutation bars extends transversely beneath the key levers 46- and haveformed on the upper edges thereof different arrangements of `notches.

Only one of the permutation bars 5I is shown in order 'to simplify the drawings, there -normally being as many permutationbarawhich in morst keyboards is five, as there arevariablesignalling impulses in each transmitted code group. On

thereof a plurality of notches or sloping surfaces 55, one for each key lever. VThe notches or slopingv surfacesj are so arranged that the release bar'52moves toward the left whenever any one ofthe key levers 46 is actuated. The release bar Y52 'and the permutation bars 5I are suitably guided .in .brackets (not shown) and rest upon individual rollers such as 53 on pivot rods such as54.r"` .I 'j

'lfhegrightha'ndiend ofthe release bar 52 has a 4vertical bifurcation 'therein which engages a pin 56 extending from the forward depending end of a lever 51 'which is pivotally mounted at the rear end thereof on a shoulder screwy58 extending from a, section 590i ther frame. The lever 51 has attachedadjacent'the center thereof by a shoulderscrew-GJ the left hand' end of a link (2, the'right;hand endof4 which is `pivotally mounted on a shoulder of thestud 44.` When the release bar 5 2 moves toward the left on the actuation'of a key lever 46, it causes through the 1ever51 andthe link 62 the'piyot plate 34'to pivot a slight amount 'in a' counterclockwise Adirection againstthe. action of thespring 31.` This piv- VotingV ofthel plate 34 causes the'ngerB of the left hand blocking'member 32 to move Voutfrom beneath the'end of the' arm 3|- on the normal 'gate stop 22. ,Thereupon the gate stop 22 is no longer blocked and the stop arm; I9 and, transmitting shaft'I3 are free to rotate through the action of the friction clutch I4. When thestop arm I9 rotates a suicientamount to clear the projection' 29 on the stop gate 22, the attached spring 21 pivots the same in aclockwise direction back into engagement with the stationary stop Y 28.'. AInthis position the projection 29 of the blocking member32 is again in the path of the normal stop arm I9 toV reengage the same near the end of: a revolution of the transmitting shaft. Reengagement of the vstop arm I9 with the stop gate 22Y pivots `the latter to bring the end of the arm Y3| into Vengagement -with the top of the finger 30 of the left hand blocking member 32 and thus stops further rotation of the transmitting shaft I3 after one rotation thereof. In

. the above described cycle of operation it was assumed'that the key lever effecting the release of the transmitting shaft I3 was promptly released or released some time before the shaft completed a revolution. This allows the spring 31 to return the pivot plate 34 and attached elements to their normal positions,4 which returning operation includes the return ofthe nger 33 beneath the stop gate 22.: Thus thetransmitting shaft I3 is released for one revolution ata time on the actuation of a key lever 43-and is stopped in its normal stopped position following the revolution.

In the preferred embodiment of the invention the arms 43v holding the blocking) members 32 apart against the action of the spring 4I are so adjusted that just before the finger 30 of the left'hand blocking member moves out from beneath the arm 3I of the stop gate 22A, the inner end of the flnger 30 on the right hand blocking member moves beneath its associated stopgate 23. Thus, in normal operation-of the keyboard at least one of the fingers 3|)Yisinvariably in position to block their associated stop gatesr- 22 or 23. Normally-the stop gate 23` does not function to stop .the transmitting shaft. It only functions to stop the shaft when an operated key lever is held depressed for an abnormal length of time or for a length of time longer than that necessary to transmit the code group. When a key lever 46 is released before thershaft I3 has made a complete revolution from its normalrest position, the nger 3B' on the left hand blocking member is moved by theraction of the spring 3l back in its normal position to block the stop gate 22 which in turn stops the -shaft I3 after one complete revolution. Just before the shaft I3 completes a revolution the auxiliary stop arm 2| engages the projection 29 on the auxiliary stop gate 23 to pivot the same in a counterclockwise direction against its attached spring 2'I. If at this time the key lever 46 which cause the release of the transmitting shaft has returned to its unoperated position and allowed the spring 3'I to pivot the pivot plate 34 to its normalrporsition, the finger 30 on the right hand gate stop will be out of operative relation with the arm 3| of the auxiliary stop gate 23. Hence, the stop arm 2| is permitted to pivot the stop gate 23 with the end of the arm 3| thereof moving down past the inner end of the right hand blocking member 32 and consequently the stop gate 23 is not effective to stop the shaft |3. As the auxiliary stop arm 2| clears or rotates out of operative relation with the projection 29, the spring 2? returns the auxiliary stop gate to its normal position against the stop 28. The stop arms I9 and 2| are so positioned on the shaft I3 that this unblocked pivoting of the auxiliary stop gate 23 occurs just prior to the engagement of the normal stop arm I9 with its associated stop gate 22. Thus, in normal operation of the keyboard or when a key lever is released prior to the transmission of a code group, the auxiliary stop gate 23 does not function to stop the transmitting shaft I3. However, as will now be described, the auxiliary stop gate 23 stops the transmitting shaft in an off-normal position when a key lever is held depressed or operated for an abnormal length of time.

The positions of the ngers 3D of the blocking members 32 relative to their associated stop gates 22 and 23 are shown in Fig. 3 in the normal positions by the full outline thereofrwhich are their positions with all the keyYV levers 46 unoperated. The dot-dashed outline of the ngers 3|) of the blocking members 32 shows the same in their operated positions or the positions they assume when a key lever 4E is operated or held operated. With a key lever 43 held operated, the fingers 33 remain in such positions where the end of the nger 3|! on the right hand blocking member 32 is beneath or in the path of the end of the arm 3| on its associated auxiliary stop gate 23. Hence, near theend of a revolution of the transmitting shaft I3, when a key lever is held operated, the stop arm 2| will engage the stop gate 23 to pivot the same a slight amount to'bring the end of the projection 3| thereon into engagement with the upper side of its associated finger 30. This stops further rotation of the transmitting shaft in an off-normal position, and the same will remain stopped as long as the blocking members 32 remain in their op- R, the same as when stopped in its normal poc sition. Y

With the transmitting `shaft I3 stopped in its olf-normal stop position the subsequent release of the actuated key lever 46 permits the returnv of the blocking members to their normal positions and during such movement the finger 3D of the right hand blocking member moves out from beneath its associated stop gate 23 just` after the finger 30`on the left hand blocking member moves beneath itsassociated stop gate 22. The movement of the finger 3D from beneath the stop gate 23 releases the shaft I3 and allows the same'to rotate until the normal stop arm I9 engages its associated stop gate to stop the shaft in its normal stop position as at this time nger 3|) is beneath the said stop gate 22. Thus, on the actuation of a key lever 46, whether orV` not it is' released immediately or'held depressed for an extended length of time, 'the transmitting shaft |3 will make but one complete revolution. It will be noted that the horizontal arms of the stop gates 22 and 23 are considerablyv longer than the arms or projections 29, and therefore the pressure of the arms 3| on the fingers 30 of the blocking members 32 is correspondingly less than the pressure of either one of the stop arms I3 or 2| on the projections 29 when the shaft I3 is stopped. Thus the fingers 3D may be more easily Withdrawn from blocking engagement with the stop gates than if the 1ingers blocked the stop arms I9 and 2| directly. Such an arrangement imposes less load on the key levers and permits easier operation or a lighter touch If a key lever is released before the stop arm I9 has cleared or rotated out of operative relation with its associated stop gate 22, the latter mayV not have had suilicient time to pivot back into engagement with the xed stop 28 before the end of the finger 30 on the left hand blocking member 32 starts to move or has completely moved back to its unoperated position. Thus the lfinger 30 may be above and in the path of the arm 3|. However, the engagement of the top of the arm 3| with the underside of the iinger A3|) will not prevent the movement of the arm 3| back into engagement with the fixed stopY 28 as the underside of the finger 30 is sloped and such engagement of the two elements cams the blocking member to the left to permit the arm 3| to clear the finger. The strengths of the springs 27 and 4I are such that the spring 4I has little effect in retarding the return of the arm 3| into engagement with the fixed stop 28. Thus, the stop gate 22 is not prevented from returning to its unoperated position where it can again cooperate with the nger 33 to stop the shaft I3 after one revolution thereof.

Each of the permutation bars 5|, as shown in Figs. 1 and 4, has extending from the right hand ends thereof projections 64 which are adapted to cooperate with associated pieces of insulating material B6, .such as Bakelite, carried on the left hand end of associated individual contact levers 61. The contact levers 61, one for each permutation bar 5|, are pivotally supported adjacent their centers on a horizontal pivot rod 68, and each has adjacent its right hand end a contacting element 69. The contacting elements 6 3 are Aadapted to cooperate with other'fixed contacting elements 1| individually supported in a common insulating. support 12. Individual springs 1.3 attached to thecontact levers 61tend to pivot the same in a counter-clockwise directionto effect engagement off-the movable vcontact elements thereon with associated fixed con.- tact elements 1|. The contact levers 61 and the springs 13 are insulatively supported from the rest of the keyboard and have Apotential applied thereto lso that when the contacting 'elements 69 and 1| engage, potential is applied to the fixed contacting elements 1|.V -v

l The projections 64 on the permutation bars I 'and the segments 66 on the contacty levers 61 are so arranged that with a permutation bar in its`left'hand position, as shown by the full outline thereof in Fig. 4, the associated contact lever 61 is 'pivoted by itsfattached spring 13 to bring the contacting Yelements 69 and 1I together. The movement of a'perrnutationbar 5| from its left to its right hand position eifectsengagement of the elements 64 and,66 which in turn causes the associated contact lever 61 to pivot a slight amount in a clockwise direction and disengage the movable contacting element 69 from the fixed contacting element 1|. The permutation bars 5I are moved into their left and right hand positions in various combinations depending 'upon which of the key levers 46 are'actuated and they thus in turn condition the setsof contacting elements 69 and 1I in open or closedpositions to correspond with the positions of the permutation bars.

The-fixed contacting element 1| of each set is connected by an individual conductor, such as.

I -tuated key lever, and as th'ebrush |4 subsequently bridges these segments with the solid ring: I6. the brush being released in conjunction with the operation of the key lever, as set forth above, a code group of impulses Vrepresentative of the Thus potential is applied to the of the transmitting shaft I3 the cam al pivots 'vate' the bail back to its normal position.

thebail 16 s'o that the knife Section 82 engages either one side or the other of the projections 83 to-prevent re-movement thereof until' near the end ,of the revolution of the transmitting shaft VI3.wlf1en the cam 8| permits the'spring 84 to elethis manner the knife section 82 locks the permutation bars 5| and'prevents movement thereof during substantially all rotationof the trans- 1nittingshaft-I3.

actuated key lever is transmitted'to the sending circuit or line L. The brush I4 just after leaving its rest position orthe rest segmentV R. bridges a start segment ST with the solid ring and as the start segment is dead, an impulse or open line condition is transmitted to the line preceding each code group of impulses as is the usual practice in start-stop signalling. On the completion of a revolution of the brush I4 it contacts the rest segment R to transmit the rest or closed line impulse following eachcodeV group.

In order to prevent the actuation of a second key lever until after the transmission of a code group representative of a previously. actuated key lever, a locking bail 16 is employed; The locking bail 16 is pivoted at 11, Fig. 1, and has an upwardly extending arm 18 which carries a cam follower 19 in operative relation with the periphery of a cam 8| fixed to the transmitting shaft I3 for rotation therewith. The bail VV16 has fixed thereon a knife 'member 82, wedgeshaped on the lower edge, which is adapted to cofVV operate with upwardly .extending wedge-shaped It is obvious, of course, that various modifications of the invention may be made without departing-.from the spirit or essential attributes thereof, and it is desired therefore that only such limitations be placed thereonas are imposed by the prior art or are specifically set forth in the appended claims.

What is claimed is: 'y 1. Inattelegraph keyboard, `a rotatable distributor mechanism for distributing code groups of impulses representative of actuated key levers to' asending circuit, a pair of stop arms rotatable with vsaid distributor, individual stop gates associated with eachof said stop arms, blocking members ,for each of said stop gates, the first of said blocking members normally blocking one of said stop gates whereby the latter through the associated stop arm maintains said distributor atrest in a normal position, solely mechanical means controlled by the actuation of said key levers for moving said first blocking member out of blocking relation with said associated stop gate and thereby release said distributor for rotation, and means operative on the unblocking movement of Ysaid rst blocking member to move,

with said distributor, individual stop gates associated with each of said stop arms, anindividual blocking member for each of said stop gates, a set of key levers, and solely mechanical means including said blockingk members, said stop gates and said stop arms for releasing said distributor y member for one cycle of operation and invariably stopping the same following each cycle of operation in conjunction with each operation of a key lever. Y n

3. In a telegraph keyboard transmitter mechanism, Ya cyclically operable distributor mechanism, a pair of stop arms rotatable with said distributor, anindividual stop'gate associated with each of saidA stop arms, an individual blocking member associated with each of said stop gates, means including first ones of said blocking members,Y vstop gates and stop arms for maintaining said Ydistributor at rest in a normal position, a set ofkey levers, means operative on the actuation'lof said key levers one at a time for withdrawing said first blocking member out of blocking relation with ksaid associated stop gate to thereby releasesaid distributor, means operative on the release of said key lever prior to the completion of a cycle of operation thereof `for moving said iirst,l blocking member back into blocking relation with said associated stop gate to stop said distributor followinga cycle of operation, and means including second ones of said blocking members, stop gates and stop arms for stopping said distributor on the operation of a key lever for anabnormal length of time.

4. In a telegraph keyboard transmitter mechanism, a cyclically operable distributor mechanism, a pair-of stop arms rotatable with said distributor, an individual stop gate associated with each of said stop arms, an individual blocking member associated with each of said stop gates, means including rst ones of-said blocking members, stop gates and stop arms for maintaining said distributor at rest in a normal position, a set of key levers, means controlled by said key levers for moving said blocking members out of and into blocking relation with associated stop gates to release and stop said distributor mechanism respectively, and meansY for Vinvariably maintaining at least one of said blocking members in blocking relation with an associated stop gate at all times.

5. In a telegraph keyboard transmitter mechanism, a cyclically Operable distributor mechanism, a pair of stop arms rotatable with said distributor,- an individual stop gate associated with each of said stop arms, an individual blocking member associated with each of said stop gates, means including rst ones of said blocking members, stop gatesand stop arms for maintaining said distributor at rest in a normal position, a set of key levers, means including said blocking members operative on the actuation of said key levers one at a time for unblocking said rst stop gate and blocking said second stop gate, means operative on the release of said key lever prior to the completion of substantially a complete cycle of operation of said distributor for reblocking said iirst stop gate and unblocking said second stop gate to bring said distributor to rest in normal position, means operative on the continued blocking of said second gate by the continued actuation of said key lever to stop said distributor in an off-normal position, and means operative on a subsequent release of said key lever to unblock said second stop gate and reblock said rst stop gate whereupon said distributor rotates from said oir-normal position to said normaliposition.

6. In a telegraph keyboard transmitter, a rotary distributor mechanism, a stop gate for arresting said distributor mechanism, an interponent movable into and out of the path of movement of said stop gate, resilient means, said resilient means biasing said interponent into the path of said stop gate to initiate and arrest, respectively, the rotation of said distributor mechanism; j

7. In a telegraph keyboard transmitter, arrotary distributor mechanism, astop gate ,for arresting said distributor mechanism, an 4interponent movable into and out of the path of movement of said stop gate, resilient means, said resilient means biasing said interponent into the path of said'stop gate whereby said. gate normally arrests said distributor mechanism in a normal, position, a set of key levers, solely mechanical means 'actuated by said key levers to,

move said interponent out of the path of said stop gate against the action of said resilient means to release said distributor mechanism, means including said resilient means` for moving said interponent back into the path of said stop gatel on the release of a key lever to stop said-distributor mechansmfollowing a cycle of operation there-` of, and means for preventing said interponent from blocking the movement of said stopgate in returning to a normal position ,when said interponent returns to a normal position prior to the return movement of said stop gate.

8. In a telegraph keyboard transmitter, a rotary distributor mechanism, a stop gate for arresting said distributor mechanism, an interponent movable into and out of the path of'movement of said stop gate, resilient means, saldresilient means biasing said interponent into the path of said stop gate whereby said gate normally arrests said distributor mechanism in a normal position, a set of key levers, solely'mechanicaly means actuated by said key levers to move'said interponent Youti of the path of said stop gate against the action of said resilient means to release said distributor mechanism, means including said resilient means for moving said nterponent back into the path of said stop gate on the release of a key lever to stop said distributor mechanism following a cycle of operation thereof, a sloping surface on said interponent opposite the stop gate blocking surface, and means including said sloping surface for camming said interponent out of the path of movement of said stop gate during the return movement of said stop gate when said interponent returns to. said normal position prior to the return movement of said stop gate.

9. In a telegraph keyboard transmitter, a rotatable distributor mechanism, a pair of stop gates, a pair of interponents, one for each stop gate, movable into and out of blocking relation therewith to arrest and release said distributor mechanism, a resilient means, said resilient means normally biasing the rst of said interponents into blocking relation with its associated stop gate to arrest said distributor mechanism in a normal position and the second of said interponents out l of blocking relation with its associated stop gate,

path of said stop gate whereby said gate normally arrests said distributor mechanism in a normal position, a set of key levers, solely mechanical means actuated by said key levers to move said interponent out of the path of said stop gate against the action of said resilient means to release said distributor mechanism, means including said resilient means for moving said interponent back into the path of said stop gate on the release of a key lever to stop said distributor mechanism following a cycle of operation thereof, and means for varying the amount of movement of said interponent by said key levers and said resilient means in moving out of and` into the a set of key levers, means operated by said key levers against the action of said resilient means for withdrawing therst of said interponents out of blocking relation with its associated stop gate to release said distributor mechanism and concomitantly move the second of said interponents into blocking relation with its associated stop gate whereby said second stop gate is eiective to stop said distributor following a predetermined amount of rotation thereof, and means operative on the release of an actuated key lever prior to the completion of said predetermined amount of rotation of said distributor to withdraw said second interponent from blocking rela- 6 eerste tion with its associated stop gate and concomi` tantly move said iirst interponent into blocking relation with said rst'stop gate to stop said dis` tributor in its normal position following a cycle of operation thereof. Y A 10. In a telegraph keyboard transmitter,V a rotatable distributor mechanism, a pairv of` stop gates, a pair of interponents, one for each stop gate,movab1e into and out of blocking relation therewith to arrest and Vrelease said distributor mechanism, a resilient means,y said resilient means normally biasing Athe rstof said interponents into blockingY relation with its Aassociated stop gateto arrest said distributor mechanism in a normalY position and thevsecond of said interponents out of blocking relation with its assomechanism and concomitantly move ther second of said interponents into blocking relation withl its associated stop gatefwhereby said second stop gate is effective'to stop said distributor followinga predetermined amount of rotation thereof,

means operative on the release of an actuated 1 1l. In a telegraph keyboard transmitter, a rol vtatable distributor mechanism, al pair of stop stop gate yto arrest'said distributor mechanismv in a normal'position and the second of said interponents outv ofblocking -relation with itsv associated stop gate,^a set of keyKV levers, means operated by said key levers againstthey action of said resilient means for withdrawing the first of said interponents out of blocking relation with its associated kstop gate to release said distributor mechanism and concomitantly move the second of said interponents into blocking relation with its associated stop gate whereby said second stop gate is effective to stop said distributor following a predeterminedamount of rotation thereof, means operative onfthe release of an actuated key lever priorY to the Vcompletion-oi said predeterminedV amount of rotation of said distributor to Withdraw said-second interponent from blocking relation with its associated stop gate and concomitantly move said first interponent into blockingrelation with said rst stop gate to stop said distributor in its normal position following a cycle of operation thereof, andV means for varying thedistance said -i'nterponents' move from normal lto operated positions in moving out of and into blocking relation with associated stop gates.` v Y VERNON R. KIMBALL Y ROBERT EDIRKES 

